20/05/07 01:11:02 0pZrsm5h.net
>>721
なんだ、そこにそのまま書いてあるじゃない。
つまり、alignされているなら quadword は atomically に Read/Write できる。
キャッシュラインの中に納まっているなら align されてなくても OK、と。
8.1.1 Guaranteed Atomic Operations
The Intel486 processor (and newer processors since) guarantees that
the following basic memory operations will
always be carried out atomically:
・Reading or writing a byte
・Reading or writing a word aligned on a 16-bit boundary
・Reading or writing a doubleword aligned on a 32-bit boundary
The Pentium processor (and newer processors since) guarantees that
the following additional memory operations will always be carried out
atomically:
・Reading or writing a quadword aligned on a 64-bit boundary 16-bit accesses to uncached memory locations that fit within a 32-bit data bus
The P6 family processors (and newer processors since) guarantee that the following additional memory operation will always be carried out atomically:
・Unaligned 16-, 32-, and 64-bit accesses to cached memory that fit within a cache line.